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Common Problems with Retort Measurements ǀ Salunda

A retort is traditionally used in the process of testing drilling mud for water, oil and solid content.

A drilling mud sample is taken and placed within a drilling fluid chamber of known volume. The drilling fluid lid is then placed over the top ensuring no air is trapped within the chamber and placed within the upper chamber of the retort oven.


The upper chamber of the retort oven will then be heated to around 900°F until the liquid components of the sample have been vaporized. These vapours are passed through a condenser and collected in a measuring cylinder. The operator will then take a measurement of the volume of oil and water which will have separated within the measuring cylinder, this is normally recorded in cm³.


The following formulas will be used to determine the water, oil and solid %

% Oil by volume = cm³ oil x 100/Volume of sample

% Water by volume = cm³ water x 100/Volume of sample

% Solids by volume = 100 – (cm³ oil + cm3 water) x100/Volume of sample

Further calculations can then be used to determine the weight percentages of the water and oil.

Common issues with retort measurements

Retort has been used as standard practise for measuring water, oil and solid content within drilling mud for some time. The standard procedures for usage of the retort has been published by the American Petroleum Institute (API), however there are some issues with the measuring technique.

  • Erroneous readings are common when taking traditional retort measurements. These are commonly caused when residue from the drilling fluid sample is left on the outer casing of the chamber/chamber lid or when air is trapped within the chamber.
  • Water vapour can escape from the retort and not be condensed and collected in the measuring cylinder.
  • The process of carrying out traditional retort measurements is lengthy; with testing often taking up to 90 minutes to complete, this can be an issue when drilling through complex formations where more regular testing would be beneficial to the efficiency of the drilling operation
  • The retort oven becomes hot during and after testing; posing a significant risk of burns to the operator
  • When changing mud engineers on a job change the results can vary widely from one another due to inconsistent practises

 What’s the alternative to laboratory testing?

Salunda’s MudChecker provides a viable alternative to traditional retort measurements. The handheld device uses patented sensor technology to provide accurate, repeatable results of water, oil and solid content within minutes, allowing for more regular, consistent test results whilst also being carried out in a safer environment.

Find out more about Salunda’s MudChecker by following the link below or navigating to the MudChecker product page from the website menu.





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Aberdeen Office

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United Kingdom


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